Noise-reducing typewriter platen



W. R. MULOCK.

NOISE REDUCING TYPEWRITER PLATEN,

APPLICATION FILED SEPT- 3. I921.

Patented May 9,1922.

' To all whom it may concern:

UNITED. STATES PATENT OFFICE.

I-NOISE-BEDUCING mnwmrnn rLA'rEN.

Specification of Letters Patent. jp t nt May 9' 1922 1 Application filed SeptemberB, 1921. Serial m. 498,270. I i I Be, it known that 1,; VVILLIAM Rnoronn MULooK, a subject of-the King of Great Britain, and resident of Winnipeg, in the Province of Manitoba, Dominion ofv Canada, have invented certain new and useful Improvements in Noise Reducing Typewriter Platens, ofwhich the following is a full, clear, and exact specification.

This invention relates to platens for typewriting machines and has for its object to provide a noise-reducing platen of simplified and improved construction. A special aim of the invention is to insure the production of clear impressions from the type, as well as the\deadening of the sound resulting from said type striking the platen. Anotherob'ect is to dispense with the complicated anc expensive constructions hereto fore employed for the purpose mentioned, and to produce a platen of very simple and inexpensive construction which will give superior results. Further objects will appear as the description proceeds.

The invention will be first hereinafter described in connection with the accompanying drawings, which constitute part of this specification, and then more specifically defined in the claims at the end scription.

In the accompanying drawings, wherein similar reference characters are used to designate corresponding parts throughout the several views:

,Figure 1 is a longitudinal central section of a roller platen constructed substantially in accordanc with this invention.

Figure 2 is a transverse section taken on the line II--II of Figure 1. Figure 3 is a front elevation of a stationary cylindrical platen frame similar to that disclosed in my Patent, X0. 1,382,218, dated June 21, 1921, but showing the striking sun face of the platen strip covered with celluloid, and

Figure 4 is a transvers section of the "platen frame illustrated in Figure 3 taken on the line IV-IV thereof.

Referring first to Figures 1 and 2 of the drawings. 1 designates the usual shaft which extends centrally through the roller. platen and has milled knobs on its ends. The platen is built upon a small supportlng sleeve or tube 3 which fits snugly on the shaft 1 and inay be secured to turn therewith of the dein any suitable manner as by thesetyscrews 4 in the projecting endjportions of said tube, The core or body portionfi of the platen is made of soft rubber which is preferably formed in a solid cylindrical piece fitted around the tube 3 with which it is designed to turn. Struts or projections 6 may be formed on said tube at suitable intervalsto hold the soft rubber core in place thereon and prevent it from losing its shape.

On'the'outside of the cylindrical soft rubber core 5 there is a surface member 7 of thin v celluloidor other similar substance having av smooth outer face of sufficient hardness to produce clear impressionsunder the impact of the type without being effected'tliereby, andof sufficient strength to :maintaihan even printing surface. Said surface 7 may be formed as an integral tube fitted closely around the soft rubber c-ore f) so as to turn therewith "as best illustratedfin Figure '2, but. said surface may bebuilt up of separate pieces joined together or fastened'to the: outside of the core in any suitable manner.

Referring now to Figures 3 and 4, the sta tionary platen frame8, illustrated therein, is mounted on a central shaft 9 having milled knobs 10 at its ends. A platen strip or core 11 of soft rubber is mounted in a core 11 is covered 3th a surface member 16 of thin celluloidor other suitable material of the same properties as the surface 7 on the .er platen already described in connection with Figures. 1 and 2 of the drawings. This surface member 16 may be secured to the soft rubber platen strip 11 in any suitable manner, as by an adhesive, and

the edges thereof may be bent to grip the lupper and lower faces of said strip, as illus-' trated in Figure 4, for more securely holding saidsurface member in position.

either of the forms of platens herein 110 illustrated. and described, the soft rubber core or body portion,'which constitutes the sole direct support for the hard surface member, serves to deadeii the sound which is usually produced by the striking of the type upon platens of ordinary constructions. The thin surface or 16 of celluloid, or other similar material, insures clear impressions core extending'from said supporting member to said surface member. I

2. In a typewriter platen, the combination with a supporting-member, of athin celluloid surface member, and a soft rubber core extending from said supporting member to said surface member.

3. In a typewriter platen, the combination with a supporting member, of a thin surface member of hard material, and a soft rubber core extending from saidsupporting member to said surface member and constituting the sole direct support for the lattermember.

a. In a typewriter platen, 'thecombination with a supporting member, of a thin tubular surface member of hard material, and a soft rubber'core surrounding said supporting member and extending therefrom to said surface member.

5. In .a roller'platen for typewriter machines, the'combination witlua central supporting member having projections thereon, of a soft rubber core fitted around said supporting member and retained in position thereon by said projections, and a thin covering of hard material substantially as described surrounding said core for the pur- I pose specified. I

6. In a roller platen for typewriter machines, thecombination with a central supporting member, of a soft rubber core fitted around said supporting member, there being projections onsaid member embedded in said core for holding the latter in place, and a thin covering of hard material sub stantially as described surrounding said core for the purpose specified.

In testimony whereof I'have signed my name to this specification.

WILLIAM REDFO'RD MULOCK. 

